Cold winters

The tendency of home gardeners is to think of their local climate in terms of USDA cold hardiness zone.  Hardiness zone is based on the average coldest temperature of the year, and Utah gardens range from zone 3 to zone 9.  Certainly, cold winters limit growing many fruit crops in Utah such as citrus, and other subtropical and tropical fruits.  However, although mid-winter cold temperature is important, it is usually not the major limiting factor for growing temperate climate fruit species (apple, pear, peach, cherry, etc.) in Utah.  Spring and fall temperature fluctuations are more often the climatic factor that limits the success of fruit crops.  For example, apricot trees are quite cold hardy and will survive and grow in regions with relatively severe winter temperatures.  However, in stone fruits, apricots are among the first to bloom and the developing flowers are frequently damaged by spring cold temperatures.  In many colder spots in Utah, apricot trees may only produce fruit 1 in every 5 or 6 years.  Under these climatic conditions, the utility of apricot trees becomes limited to shade.